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Timing Porsche 914s with Carbs
 
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Pelican Technical Article:

Timing Porsche 914s with Carbs

Pete Dubler

Time:

30 minutes30 mins

Tab:

$0

Talent:

**

Tools:

Timing light, metric wrench set, metric socket set

Applicable Models:

Porsche 914 (1970-76)

Performance Gain:

Get your carbs on by properly timing your carb-equipped 914

Complementary Modification:

Replace your spark plug wires
     When setting the timing for your 914 with carbs, after following all of the advice above, such as setting the dwell angle, you will need to know where to set the timing and at what RPM. Most advice of late is to set the timing at 34 to 36 degrees BTDC with the engine running at 3200RPM with the vacuum advance line to the distributor connected. This means, you have a total advance of 34 to 36 degrees when the engine is not loaded up (bogged down). Using the Bosch 205AA distributor, I found this setting to provide excellent performance and drivability at all RPMs and speeds. The vacuum advance on the distributor lets up a bit, providing some retard, when the car is under load, like when punching it pass lesser cars, thus preventing ping (predetonation) and providing a smooth acceleration.

     If you don't have an "advance" timing light, which allows one to dial in an advance and time to the TDC mark (or any other point for that matter with a little arithmetic), you need to know where on your fan to place your timing mark. Fear not, the mark is already there, but it is not "marked". Refer to the attached photo of a 1.7L fan (The 34-35 degree timing mark on the 1.8 and 2.0 fan is in the same place). The 914 fan has four thick spreaders spaced at 90 degree intervals around the fan. The first spreader to the left of the TDC mark, as viewed from the back of the car, is where you will find your mark. Note that the spreader has a raised oval mark on it. The left edge of that mark is right between 34 and 35 degrees BTDC.

     What's great about this built-in timing mark is that you can see it without having to be a contortionist. Unlike the TDC, 7.5, and 27-degree marks found on various 914 fans, which are located on the back edge of the fan, this "mark" runs all the way across the fan. (Yet another advantage for carbs?)

     To set the total advance timing, hook-up your timing light to the cylinder 1 plug cable and put on your headphones (3200 RPM can be pretty noisy with your head in the engine compartment). With the parking brake on and the car in neutral, ask one of your kids to hold the car at 3200 RPM (my kids love this "driving"), while you twist the dizzy to meet the newly found timing mark on your 914 fan.

pic1_small.JPG (2701 bytes)
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Comments and Suggestions:
Rivercityhawkeye Comments: What replacement parts are now not available for a fuel injection system for the 1972 914?
December 22, 2015
  Followup from the Pelican Staff: Pelican parts should be able to get most of them. Give our parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
 
Jim Comments: The correct way would be to disconnect and plug the vacuum line from the distributor then with a timing light on the engine run it up to 3000-3500rpm and set it for 28 degrees fully advanced. The reconnect the vacuum line to the distributor.
January 5, 2013
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help.

- Nick at Pelican Parts
 
Jeff Comments: On my 1973, 914 2.0 there are no vacuum lines. The distributor has the ports but the Weber carbs have no ports?
August 13, 2011
  Followup from the Pelican Staff: You may have to drill and tap a port into the intake manifold. I know this has to be done one some models. - Nick at Pelican Parts  

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